Various processes for the production of imidazolidinones (ethylene ureas) are known. Shenoy, P.K. et al., American Dyestuff Reporter, May 6, 1968, pp. 17-34 (352-369), discloses a variety of processes for the preparation of ethylene urea (2-imidazolidinone) and derivatives of ethylene urea. At page 18 (353), it is stated that aminoethylethanolamine and urea can be reacted at a temperature of 100.degree. C.-180.degree. C. to give N-(2-hydroxyethyl)ethyleneurea. Also, at page 18 (353), it is stated that N-(2-hydroxyethyl)ethyleneurea can be prepared from the reaction of aminoethylethanolamine and diethyl carbonate. At page 19 (354), it is stated that N,N'-(dimethyl)ethyleneurea can be prepared by reacting ethylene urea with formaldehyde followed by catalytic hydrogenation with a nickel catalyst, or by using formaldehyde-formic acid reduction of ethylene urea.
U.S. Pat. No. 2,812,333 describes a process for the production of N-(2-hydroxyethyl)ethylenediamine by reacting 2-aminoethanol and carbon dioxide at an elevated temperature and pressure to yield N-(2-hydroxyethyl)ethyleneurea which is hydrolyzed to form N-(2-hydroxyethyl)ethylenediamine.
U.S. Pat. No. 4,731,453 relates to a Process of producing 1,3-dialkyl-2-imidazolidinones directly from N,N'-dialkylethylenediamine and urea which comprises reacting a N,N'-dialkylethylenediamine with urea at a temperature of 180.degree. C. or higher in the presence of a polar solvent to obtain a 1,3-dialkyl-2-imidazolidinone.
U.S. Pat. No. 4,511,722 exemplifies the Preparation of N-(2-hydroxyethyl)ethyleneurea by reacting aminoethylethanolamine and urea at a temperature of 90.degree. C. to 230.degree. C. until the elimination of ammonia is complete.
U.S. Pat. No. 2,517,750 discloses the preparation of imidazolidinones (ethylene ureas). In particular, Example 9 thereof demonstrates the preparation of N-(2-hydroxyethyl)ethyleneurea by reacting aminoethylethanolamine and urea at a temperature of 200.degree. C.
U.S. Pat. No. 4,668,793 describes a process for producing 1,3-dimethyl-2-imidiazolidinone which comprises reacting N,N'-dimethylethylenediamine and/or its hydrochloride with phosgene in the presence of a substantial amount of water and a dehydrochlorinating agent.
U.S. Pat. No. 3,876,657 relates to a method for the preparation of 1-substituted-2-imidazolidinones wherein a tertiary amine monoimide is thermolytically rearranged to provide the 1-substituted-2-imidazolidinone.
U.S. Pat. No. 3,910,948 discloses the preparation of 1,3-diacyl imidazolidinones and hexahydropyrimidines by the reaction of formaldehyde and an N,N'-alkylenebisamide in the presence of a strong acid catalyst, the substituent acyl groups being acetyl, butyryl, pentanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, palmitoyl, stearoyl and oleoyl.
U.S. Pat. No. 4,405,794 describes a method for reacting urea and beta-hydroxyethylcarbamate to make 2-oxazolidinone and ethyleneurea whereby the reaction method can be controlled to provide either the 2-oxazolidinone or the ethyleneurea as the major reaction product.
U.S. Pat. No. 4,642,351 relates to a process for the preparation of N-substituted imidazolidinones and N-substituted 2-thionimidazolidinones which comprises contacting an oxazolidinone with a compound containing a nitrogen directly bonded to a carbonyl or a thiocarbonyl group in the presence of a Lewis acid catalyst or the hydrate of a Lewis acid catalyst under conditions such that an N-substituted imidazolidinone or N-substituted 2-thionimidazolidinone is prepared.
Nomura, R. et al., Ind. Eng. Chem. Res., 1987, 26, pp. 1056-1059, discloses the preparation of cyclic ureas from carbon dioxide and diamines catalyzed by triphenylstibine oxide.
Enichem Synthesis Spa, Dimethyl Carbonate Product Bulletin, p. 13, discloses the preparation of imidazolidin-2-ones from ethylenediamines and dimethyl carbonate in the presence of sodium alkoxide.
Dow Chemical U.S.A., Experimental Ethylene Carbonate XAS-1666.00L Product Bulletin (1982), p. 7, describes the condensation reaction of urea and ethylene carbonate to afford imidazolidinones with carbon dioxide and water as by-products. Also, the reaction of ethylene carbonate and diamines, e.g., ethylenediamine, at high temperatures, i.e., 188.degree. C.-200.degree. C., to produce imidazolidincnes is disclosed. At lower temperatures, it is stated that dicarbamates result from the reaction of diamines and ethylene carbonate.
Texaco Chemical Company, TEXACAR.RTM. Ethylene and Propylene Carbonates Product Bulletin (1987), p. 24, discloses the preparation of ethylene urea by reacting ethylene carbonate and urea in an autoclave at temperatures around 200.degree. C. followed by heating with water.